Residential entry doors are typically constructed with door threshold sill assemblies designed to seal against the weather, particularly wind and water, when the door is closed. A wide variety of door sill assemblies include adjustable threshold caps, these caps being the portion of the threshold that resides directly beneath a closed door and provides sealing contact with the bottom of the door or the door sweep. These adjustable threshold assemblies assist in creating an effective weather seal at the threshold. Adjustable caps allow an installer, or a subsequent homeowner or resident, to optimize the fit of a specific door as necessary. By adjusting the vertical clearance properly, wind and water are more effectively excluded without hampering the operation of the door.
Adjustable threshold designs attempt to balance manufacturing efficiency with the seal integrity, ease of installation and adjustability and aesthetics. Poor quality component parts and hardware variability can undermine threshold stability and sealing effectiveness. Removable parts may be improperly installed or lost prior to installation, which can also diminish sealing integrity and also result in poor appearance. Replacing non-standard hardware components may be expensive, and parts may not be readily available for shipment. Adjustment mechanisms used on aluminum threshold caps, for example, may not be used on wood threshold caps, which in turn, makes materials' management more complex when dealing both with wood cap based door sills and non-wood cap based door sills.
Thus, there is a need for an adjustable threshold assembly that improves threshold assembly stability, and facilitates efficient manufacture and installation.